1. Technical Field
The present invention relates generally to an apparatus and method for preventing a collision between vessels and, more particularly, to an apparatus and method which collect information about a counterpart vessel based on a reference vessel, predict the possibility of a collision with the counterpart vessel, and calculate an escape route after taking into consideration the relationship of an encounter with the counterpart vessel, thereby preventing a collision between the vessels.
2. Description of the Related Art
According to the current marine accident statistics, there is a tendency for marine accidents to increase annually. One of the most common types of marine accidents is a collision. Statistics reveal that most of the collisions are related to ships of less than 100 tons and also related to collisions between non-fishing boats and fishing boats and between fishing boats.
In order to prevent a collision with another vessel, the counterpart vessel must be detected, the danger of a collision must be determined by continuously monitoring the movement of the counterpart vessel via a cross-check process performed in conjunction with the counterpart vessel using a Very High Frequency (VHF) radio, an appropriate escape operation must be instituted based on the results of the determination, and the counterpart vessel also must cooperate in carrying out the appropriate escape operation.
Unlike a large-sized vessel, a small-sized vessel, such as a fishing boat subject to frequent collisions, is not commonly equipped with a detection device for detecting other vessels, for example, a radar or an Automatic Identification System (AIS). Furthermore, even if such a detection device is mounted on a small-sized vessel, the device has limited functionality. Accordingly, collisions frequently occur because the crews of small-sized vessels cannot predict collisions using radars because of the crews being not well aware of a radar floating method, or because the crews are short of a professional navigation skill or are not well acquainted with navigation regulations.
Furthermore, it was found that when collisions occurred, counterpart vessels were not detected even immediately before the collisions. It was also found that even though counterpart vessels were detected, the distances between the vessels that could be detected by the naked eye was commonly 2 to 5 miles, which corresponds to a few minutes before a collision.
In a conventional method of preventing a collision between vessels, information about vessels adjacent to a reference vessel is collected using an external device, a collision is predicted based on information about the position and speed of the reference vessel, and an alarm warning of the collision is issued based on the prediction. Furthermore, in the conventional method of preventing a collision between vessels, a collision prevention route that should be taken by the reference vessel is provided or the steering device of the reference vessel is automatically controlled in order to avoid a collision without taking into consideration navigation regulations based on the relationship of an encounter between the reference vessel and the counterpart vessel.
However, the prevention of a collision between vessels requires a cooperative operation, and the vessels should obey navigation regulations when performing cooperative escape. Therefore, escape operations that should be taken by both vessels having the possibility of a collision are different depending on the condition in which both the vessels encounter each other. Furthermore, if several vessels are navigating, a change in the navigation route of one vessel may affect other vessels, and thus other vessels adjacent to the vessel need to know about the change.
For this purpose, in the conventional method, the prevention of collisions between vessels is performed using a VHF radio. However, there is a problem with communication because multinational vessels are navigating on the sea.
As described above, it is difficult in the conventional method of preventing a collision between vessels to discuss information about navigation and a method of escape because there is a problem with communication. Furthermore, the conventional method is problematic in that a reference vessel cannot conduct communication via a designated frequency because of the disruption of a VHF radio when the reference vessel encounters several vessels on a route with heavy traffic.